Impact of weather parameters in the development Phomopsis blight and fruit rot of brinjal (Solanum melongena)

Abstract

Role of weather parameters, such as rainfall, relative humidity and temperature in the development leaf blight and fruit rot [Phomopsis vexans (Sacc. & Syd.) Harter] of brinjal (Solanum melongena L.) during 2007 and 2008 was studied by performing correlation and regression analysis. Per cent leaf blight and fruit rot (incidence and intensity) recorded during 2007 and 2008 was correlated with the weather parameters and were subjected to regression analysis. The correlation of pooled data for both the years and weather parameters [rainfall, relative humidity (morning and evening) and temperature (maximum and minimum)] revealed that relative humidity (morning) had a positive and significant effect on leaf blight and fruit rot (incidence and intensity), whereas, relative humidity (evening) and temperature (maximum and minimum) had negative but significant effect on the disease development. Multiple correlation coefficients during 2007 and 2008 indicated strong relationship between leaf blight and fruit rot (incidence and intensity) and weather parameters, thereby establishing that rainfall, relative humidity (morning and evening) and temperature (maximum and minimum) had cumulative effect during the course of disease development and induced more than 98.1% variation in leaf blight incidence and 97.2% in intensity, whereas, it contributed more than 96.9% variation in fruit rot incidence and 96.6 per cent in intensity (pooled).